| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20210729223610.29373-17-james.morse@arm.com>
Date: Thu, 29 Jul 2021 22:36:06 +0000
From: James Morse <james.morse@....com>
To: x86@...nel.org, linux-kernel@...r.kernel.org
Cc: Fenghua Yu <fenghua.yu@...el.com>,
Reinette Chatre <reinette.chatre@...el.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
H Peter Anvin <hpa@...or.com>,
Babu Moger <Babu.Moger@....com>,
James Morse <james.morse@....com>,
shameerali.kolothum.thodi@...wei.com,
Jamie Iles <jamie@...iainc.com>,
D Scott Phillips OS <scott@...amperecomputing.com>,
lcherian@...vell.com, bobo.shaobowang@...wei.com
Subject: [PATCH v1 16/20] x86/resctrl: Move mbm_overflow_count() into resctrl_arch_rmid_read()
resctrl_arch_rmid_read() is intended as the function that an
architecture agnostic resctrl filesystem driver can use to
read a value in bytes from a counter. Currently the function returns
the mbm values in chunks directly from hardware. When reading a bandwidth
counter, mbm_overflow_count() must be used to correct for any possible
overflow.
mbm_overflow_count() is architecture specific, its behaviour should
be part of resctrl_arch_rmid_read().
Move the mbm_overflow_count() calls into resctrl_arch_rmid_read().
This allows the resctrl filesystems's prev_msr to be removed in
favour of the architecture private version.
Signed-off-by: James Morse <james.morse@....com>
---
arch/x86/kernel/cpu/resctrl/internal.h | 2 --
arch/x86/kernel/cpu/resctrl/monitor.c | 42 ++++++++++++++------------
2 files changed, 23 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index eca7793d3342..2d0a6bba4a01 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -280,7 +280,6 @@ struct rftype {
/**
* struct mbm_state - status for each MBM counter in each domain
* @chunks: Total data moved (multiply by rdt_group.mon_scale to get bytes)
- * @prev_msr: Value of IA32_QM_CTR for this RMID last time we read it
* @prev_bw_chunks: Previous chunks value read when for bandwidth calculation
* @prev_bw: The most recent bandwidth in MBps
* @delta_bw: Difference between the current and previous bandwidth
@@ -288,7 +287,6 @@ struct rftype {
*/
struct mbm_state {
u64 chunks;
- u64 prev_msr;
u64 prev_bw_chunks;
u32 prev_bw;
u32 delta_bw;
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index aa85cfd95904..39f7e74a4236 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -164,9 +164,20 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d,
memset(m, 0, sizeof(*m));
}
+static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
+{
+ u64 shift = 64 - width, chunks;
+
+ chunks = (cur_msr << shift) - (prev_msr << shift);
+ return chunks >>= shift;
+}
+
int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
u32 rmid, enum resctrl_event_id eventid, u64 *val)
{
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
+ struct arch_mbm_state *m;
u64 msr_val;
if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask))
@@ -188,7 +199,13 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
if (msr_val & RMID_VAL_UNAVAIL)
return -EINVAL;
- *val = msr_val;
+ m = get_arch_mbm_state(hw_dom, rmid, eventid);
+ if (m) {
+ *val = mbm_overflow_count(m->prev_msr, msr_val, hw_res->mbm_width);
+ m->prev_msr = msr_val;
+ } else {
+ *val = msr_val;
+ }
return 0;
}
@@ -319,19 +336,10 @@ void free_rmid(u32 rmid)
list_add_tail(&entry->list, &rmid_free_lru);
}
-static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
-{
- u64 shift = 64 - width, chunks;
-
- chunks = (cur_msr << shift) - (prev_msr << shift);
- return chunks >>= shift;
-}
-
static int __mon_event_count(u32 rmid, struct rmid_read *rr)
{
- struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r);
struct mbm_state *m;
- u64 chunks, tval = 0;
+ u64 tval = 0;
if (rr->first)
resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid);
@@ -354,13 +362,11 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
if (rr->first) {
memset(m, 0, sizeof(struct mbm_state));
- m->prev_bw_chunks = m->prev_msr = tval;
+ m->prev_bw_chunks = tval;
return 0;
}
- chunks = mbm_overflow_count(m->prev_msr, tval, hw_res->mbm_width);
- m->chunks += chunks;
- m->prev_msr = tval;
+ m->chunks += tval;
rr->val += get_corrected_mbm_count(rmid, m->chunks);
@@ -375,14 +381,12 @@ static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
{
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r);
struct mbm_state *m = &rr->d->mbm_local[rmid];
- u64 tval = 0, cur_bw, chunks, bw_chunks;
+ u64 tval = 0, cur_bw, bw_chunks;
if (resctrl_arch_rmid_read(rr->r, rr->d, rmid, rr->evtid, &tval))
return;
- chunks = mbm_overflow_count(m->prev_msr, tval, hw_res->mbm_width);
- m->chunks += chunks;
- m->prev_msr = tval;
+ m->chunks += tval;
bw_chunks = get_corrected_mbm_count(rmid, m->chunks);
cur_bw = (bw_chunks - m->prev_bw_chunks) * hw_res->mon_scale;
--
2.30.2
Powered by blists - more mailing lists